Paul Ryan is a disappointment. That's more difficult for me to write than it should be. My approach to politicians has generally been similar to that of lab researchers to their test animals: Do not get too attached. For scientists, it's a lot easier to stick a guinea pig with a needle if you know it as "test subject 43A" than if you know it as "Mr. Fluffy." For the columnist, it's easier to twist the knife if you don't feel personally invested.

But philosophically and temperamentally, I've long felt that Ryan is my kind of politician, and that judgment didn't change after getting to know him (which is rare, given how most politicians are all too human). His vision for government's role and the kind of party the GOP should be has always resonated with me, even if I didn't agree with him on every policy or vote.

For those reasons I wasn't just pleased that he held the line against Donald Trump, I was proud. And for those reasons, his endorsement of Trump was a true disappointment.

On May 5, Ryan announced that he wasn't ready to endorse. Trump instantly retorted: "I am not ready to support Speaker Ryan's agenda."

Ryan is no naif. His stance was both strategic and principled. We were told that he was giving his GOP caucus "cover" so they wouldn't all have to bend the knee to King Trump at once.

Moreover, Ryan implied that he was holding out in order to push Trump in a more conservative direction; the businessman would have to show good faith and rein in his antics in exchange for party unity. GOP apparatchiks reassured the scattered holdouts, particularly among donors, that Trump would soon stop the scorched-earth insults and histrionics and get on board with the GOP agenda. Even Trump's supporters, such as Sen. Jeff Sessions of Alabama, insisted that the presumptive nominee would "get better."

But Trump never showed signs of improvement. He attacked New Mexico's popular Republican governor, Susana Martinez, for the effrontery of not supporting him. And he vilified the Indiana-born judge in his Trump University fraud case for being a "Mexican."

Admittedly, Ryan's endorsement was about as grudging as possible. He announced it on Thursday in a local Wisconsin newspaper. In a video interview with the Associated Press, he showed all the sincerity of a POW muttering into a captor's camera. Ryan said he was "confident" that Trump would help him advance his agenda. Alas, he didn't blink "just kidding" in Morse code.

In throwing his support to Trump, Ryan made two mistakes. The first was tactical.

Because Trump did nothing to earn Ryan's endorsement, the presumptive nominee may conclude that he needn't negotiate with the GOP establishment; he can just count on its eventual submission.

As the Washington Examiner's Philip Klein put it, "If Ryan can't stand up to candidate Trump, why should we expect he'd stand up to a President Trump?"

Ryan also jeopardized the party's long game. Ryan understands better than most that the biggest hurdle for conservatives is how their motivations are perceived. If someone starts out thinking you're greedy, mean-spirited or bigoted, they're not going to listen to your 10-point plan. Ryan has been fighting that perception all his political life.

Trump often embraces that perception, proving conservatism's harshest critics right. For example, the left says conservatives support "wars for oil." Trump says that "taking the oil" of Iraq and Libya should be a top priority. Democrats claim that conservative immigration and national security policies stem from animosity toward Latinos and Muslims. Ryan's honest retort to such claims is that he abhors identity politics. Meanwhile, Trump is perfectly comfortable saying that an American judge's Latino heritage is disqualifying. On Sunday, he said the same might hold for Muslim judges.

From entitlements to trade to the First Amendment, Trump has made it clear that his vision of government isn't Ryan's. And the gulf in temperament and tone between the two men is wider and deeper than the Marianas Trench.

Trump, then, poses an Aesopian challenge to Ryan; the scorpion must sting the frog because that is its nature. The only way to avoid the sting is not to ally yourself with the scorpion in the first place. Trump will fade one day, but even Ryan's halfhearted embrace of Trumpism makes it more likely Ryanism will fade too.